In a Long Term Evolution (LTE) system, states of user equipment (UE) includes an idle state and a connected state. The UE in the idle state cannot transmit uplink/downlink data. Currently, the connected state and the idle state are switched based on a keepalive timer. When the UE does not transmit data, the keepalive timer is enabled. If no new data is transmitted within a runtime of the keepalive timer, a network configures the UE to enter the idle state after the keepalive timer expires. When the UE is in the idle state, regardless of a data size, the UE needs to be switched from the idle state to the connected state as long as there is data to be transmitted, to perform data transmission, and switching from the idle state to the connected state generates relatively high signaling overheads. When the UE transmits only a small volume of data, the UE is switched from the idle state to the connected state, causing a waste of signaling resources and increasing energy consumption of the UE.